It’s no secret that Manchester United‘s lack of quality in the middle of the park has plagued them all season.

Throughout the final years of his Red Devils tenure, Sir Alex Ferguson ill-fatedly devoted much of his attentions in the transfer market to sourcing a highly-talented central midfielder, with Chelsea’s John Obi Mikel, Tottenham’s Moussa Dembele and former Inter Milan star Wesley Sneijder representing just a few of the Scot’s many midfield targets that never materialised at Old Trafford.

David Moyes went onto inherit United’s most fatal flaw, further amplified by Paul Scholes hanging up his boots for the second and final time last summer.

Fellow Evertonian Marouane Fellaini proved to be no solution – understandably so considering the 6 foot 4 Belgium international is a polar opposite of the ex-England playmaker in every manner possible – and the next United manager, most likely Louis Van Gaal, will now enter the summer transfer window with a solution to United’s centre-mid conundrum his leading, most costly priority.

Yet the torrid saga of Manchester United’s engine room could have been so different if the Premier League champions had done more to stop France international Paul Pogba from joining Juventus in summer 2012.

The 21 year-old made just three Premier League appearances during three years at Old Trafford and in his seven senior outings across all competitions was never issued a star. Yet since joining the Turin ranks, Pogba has emerged as a key performer for Antonio Conte’s side, featuring 27 times last season as Juve lifted the Serie A title and 33 times this year as they stand just two points away from retaining it.

He may be no like-minded reincarnation of Paul Scholes, but anointed as Europe’s Golden Boy in 2013 – an incredibly honorary individual accolade previously won by Wayne Rooney, Lionel Messi, Cesc Fabregas, Mario Balotelli, Mario Gotze and Isco (and bizarrely Manchester United’s Anderson in 2008) – and listed as one of the continent’s ten most promising youngsters by the Guardian in January 2014, for the Red Devils, Paul Pogba will always be the one that got away.

Never has this been more prevalent than throughout the current campaign. Whilst Michael Carrick, Tom Cleverley and Darren Fletcher have amassed a combined total of just two goals, two through balls and no assists all season, Pogba has claimed seven strikes and six set-ups in 33 Serie A outings.

More than merely a creative influence however, the Juve midfielder is famed for his dynamic, gut-busting displays, and through his combination of guile and athleticism, many have compared the Frenchman to World Cup-winning Arsenal great Patrick Viera. United’s engine room could certainly do with that injection of brawn, pace and class amid its current malaise. They haven’t been privy to a box-to-box midfielder ever since Darren Fletcher’s health took a turn for the worse.

So why did it never work out for Pogba at Old Trafford? Well, it was never an issue of quality, that much is clear despite what the Frenchman’s omission from Sir Alex Ferguson’s 350-page autobiography might initially suggest. In fact, his absence from the book is incredibly telling.

Even before Pogba went to Juve and quickly emerged as a future world-beater, he captained France’s U16s to an Aegean Cup rout in 2009 and dazzled the Old Trafford crowd during one of his rare Premier League cameo outings against Stoke City. Fans, pundits, the United and the France set-up all had high hopes for the midfielder’s immediate future.

Rather, according to Sir Alex Ferguson, the Juventus star’s youthful arrogance and disrespect for the club always stood in the way of his long-term future at Carrington. Resultantly, he told MUTV that he was ‘quite happy’ to see the then-19 year-old leave.

Pogba paints a rather different picture however – one of the club, and specifically Ferguson, being disrespectful to him, which in turn will prevent him from ever returning to Old Trafford.

In January, the 21 year-old revealed he was ‘disgusted’ by Ferguson’s team selection on his 70th Birthday. Against Blackburn Rovers in December 2011, a match the Red Devils went on to lose 3-2, the retired United icon chose right-back Rafael over Pogba to start at the heart of midfield. In fact, the Frenchman didn’t even make it onto the pitch that afternoon. A day later, the January window opened. Having entered the final six months of his Old Trafford deal, Pogba felt ‘nothing to regret’ about opening contract negotiations with his Juventus.

These revelations have been further backed up this morning, with BBC Sport, The Express, The Guardian and the Daily Mail all reporting on Pogba’s claimed mistreatment during his final season in the Carrington ranks. According to the Juve midfielder; They left me out because they said I wanted to leave. That is disrespect. Maybe they didn’t think if they were making a mistake. You have to play. The coach told me there would be space to play, but I wasn’t playing. I was training alone for one week. They told me to go in the gym. I said “I am not an athlete, I am a footballer.”‘

It’s astonishing stuff but hardly implausible. If there’s one thing Sir Alex Ferguson proved time and time again throughout his United career, it’s that he doesn’t tolerate any form of dissidence. Pogba knew that he was good enough and Ferguson did too, but to the Scot, a player so young, ambitious and confident – bleached blonde streaks in his hair and all – can pose a great danger to those around him. Nothing could haunt Fergie more than the notion of the rest of the squad following the Frenchman’s lead and start thinking for themselves.

That ruthless strangle of power is what made Ferguson such a successful manager and Manchester United such a successful club, but in Pogba’s case it’s come back to bite them. Juventus have admitted that they may struggle to hold onto their rising star this summer if his £40million valuation is met by one of Pogba’s many, many lucrative suitors, but if one potential transfer destination can be firmly ruled out, it’s undoubtedly Old Trafford.

Having enjoyed his time in Manchester however, even claiming himself to be ‘a Mancunian’, the final act of Pogba’s sweet revenge may come in the form of joining Manchester City this summer.